I'll read through the provided links. thanks very much indeed, Dan! Samuel. On 5 March 2012 13:29, Dan Bretherton <d.a.bretherton at reading.ac.uk> wrote: > > On 03/05/2012 09:39 AM, gluster-users-request at gluster.**org<gluster-users-request at gluster.org>wrote: > >> Date: Mon, 5 Mar 2012 10:29:22 +0100 >> From: samuel<samu60 at gmail.com> >> Subject: adding bricks of diferent size to gluster >> To:gluster-users at gluster.org >> Message-ID: >> <CAOg=WDch3b72zN54B-11jQ_**FPbF6MDe8qV86p1KfBG4jY76Mjg@** >> mail.gmail.com<WDch3b72zN54B-11jQ_FPbF6MDe8qV86p1KfBG4jY76Mjg at mail.gmail.com> >> > >> Content-Type: text/plain; charset="iso-8859-1" >> >> >> Dear all, >> >> I've been trying to locate documentation about gluster functionality about >> using bricks of diferent sizes and did not find anything useful. >> >> What I was trying to answer was: >> >> *How does using bricks of different size in a distributed replicated >> volume >> affects performance? >> >> I think I read somewhere that it was highly advisable to use bricks of the >> same size but I can not locate where I read such statement? Is it true? >> >> Case it's depending on the version, I'm using mostly 3.2.4 version. >> >> Thank in advance, >> Samuel. >> > Samuel, > The mechanism described in the following gluster-users posting describes > how non uniform brick sizes are managed by GlusterFS. > > http://gluster.org/pipermail/**gluster-users/2011-September/**008754.html<http://gluster.org/pipermail/gluster-users/2011-September/008754.html> > > I don't know if this approach carries a performance penalty, but I decided > to move away from non uniform brick sizes because this configuration is not > rigorously tested by the developers, as explained in the gluster-users > posting below. > > http://gluster.org/pipermail/**gluster-users/2011-May/007788.**html<http://gluster.org/pipermail/gluster-users/2011-May/007788.html> > > The posting below describes how I have set up uniform brick sizes despite > having different sized servers in my cluster. > > http://gluster.org/pipermail/**gluster-users/2011-August/**008597.html<http://gluster.org/pipermail/gluster-users/2011-August/008597.html> > > If you are considering using non uniform brick sizes please make sure that > you set the min-free-disk parameter to an appropriate value in gigabytes. > I originally had non uniform brick sizes in my cluster and I had a lot of > problems with small bricks filling up before larger bricks, resulting in > "device full" errors even when there was plenty of space left in the > volume. The solution I eventually found is described in the following > gluster-users posting. > > http://gluster.org/pipermail/**gluster-users/2011-November/**009176.html<http://gluster.org/pipermail/gluster-users/2011-November/009176.html> > > The "device full" problem was caused by the default value of min-free-disk > being defined as a percentage rather than as a value in gigabytes. To set > the min-free-disk parameter to a value in GB follow the instructions > described in the following gluster-users postings. > > http://gluster.org/pipermail/**gluster-users/2011-May/007794.**html<http://gluster.org/pipermail/gluster-users/2011-May/007794.html> > http://gluster.org/pipermail/**gluster-users/2011-August/**008579.html<http://gluster.org/pipermail/gluster-users/2011-August/008579.html> > > It is important to make sure the value of min-free-disk is big enough. I > found that setting the value to 10% of the size of the smallest brick > seemed to work, but when I set it to only ~1% of the brick size I still had > problems with "device full" errors. > > > I hope this helps. > -Dan. > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://gluster.org/pipermail/gluster-users/attachments/20120305/39ced18c/attachment.htm>
